Small Additional Reduction Research Articles

Physical activity volume, frequency, and intensity: Associations with hypertension and obesity over 21 years in Australian women

BackgroundOptimal patterns of accrual of recommended levels of physical activity (PA) for prevention of hypertension and obesity are not known. The overall aim of this study was to investigate whether different patterns of accumulation of PA are differentially associated with hypertension and obesity in Australian women over 21 years. Specifically, we investigated whether, for the same weekly volume of PA, the number of sessions (frequency) and vigorousness of PA (intensity) were associated with a reduction in the occurrence of hypertension and obesity in women. MethodsData from the 1973–1978 and 1946–1951 cohorts of the Australian Longitudinal Study on Women's Health were analyzed (n = 20,588; 12%–16% with a Bachelor's or higher degree). Self-reported PA, hypertension, height, and weight were collected using mail surveys every 3 years from 1998/2000 to 2019/2021. Generalized Estimating Equation models with a 3-year lag model were used to investigate the association of PA volume (metabolic equivalent min/week) (none; 33–499; 500–999; ≥1000, weekly frequency (none; 1–2 times; 3–4 times; 5–7 times; ≥8 times), and the proportion of vigorous PA to total volume of PA (none; 0%; 1%–33%; 34%–66%; 67%–100%) with odds of hypertension and obesity from 2000 to 2021. ResultsThe cumulative incidence of hypertension was 6% in the 1973–1978 and 23% in the 1946–1951 cohort; 27% of women in the 1973–1978; and 15% in the 1946–1951 cohort developed obesity over the period. Overall, a higher volume of PA was associated with reduced odds of hypertension and obesity. When the volume of PA was considered, the odds of hypertension did not vary according to the frequency or intensity of PA. However, increased proportion of vigorous PA to the total volume of PA was associated with a small additional reduction in the risk of obesity. ConclusionPA volume appears to be more important than the pattern of accumulation for the prevention of hypertension and obesity. Incorporating more sessions, particularly of vigorous-intensity PA, may provide extra benefits for the prevention of obesity.

Life cycle assessment and life cycle cost of repairing surgical scissors

PurposeThe primary objective of this study was to evaluate the environmental impact and financial cost of repairing surgical scissors.MethodsWe used life cycle assessment (LCA) and life cycle cost analysis to estimate environmental impacts and financial cost of repairing surgical scissors. The functional unit was one use of a reusable surgical scissor (manufactured in Germany and used in the UK), and three baseline scenarios were compared: no repair, onsite (hospital), and offsite (external contract) repair. This ‘cradle-to-grave’ analysis included raw material extraction, manufacture of scissors and materials within primary and secondary packaging, transportation, decontamination, repair (where relevant), and waste disposal. Primary activity data was sourced from the instrument manufacturer, supplier, and from UK repair centres (both onsite and offsite), whilst the Ecoinvent database was used as a secondary data source for the manufacture of scissors. The World ReCiPe Midpoint and Endpoint Hierarchist method (Version 1.1) was used for environmental impact assessment. Scenario analysis was used to evaluate the impact of altering different assumptions, including number of uses, reducing number of repairs, increasing distance to offsite repair centre, and alternative electricity sources and waste handling processes. Life cycle cost analysis was calculated based on purchase cost, and cost of decontamination, repair, and waste disposal.Results and discussionThe carbon footprint of reusable scissors was 70 g CO2e per use, assuming scissors were used 40 times before replacement. This was reduced by 19% through use of offsite repair every 40 uses (57 g CO2e/scissor use), with small additional reductions associated with onsite repair (56 g CO2e/scissor use). Similar patterns of reduction were calculated for eighteen midpoint environmental impact categories (mean impact reduction of 30% for those repaired offsite relative to no repair) and also across three endpoint categories. Decontamination made the biggest contribution to the carbon footprint across all baseline scenarios (76% where no repair, 95–97% where repaired offsite and onsite respectively). Findings were robust to alternative scenario analyses. Life cycle cost was GBP £1.43 per use of reusable scissors, and when repaired either on- or offsite this decreased by 32% to GBP £0.97 per use.ConclusionRepairing surgical scissors rather than replacing them with a new pair can reduce environmental and financial cost. The extent to which repair may play a role in mitigating the environmental impact of other surgical instruments requires further research.

Commentary: Electronic Nicotine Delivery Systems: Seeing Through the Clouds.

Commentary: Electronic Nicotine Delivery Systems: Seeing Through the Clouds.

Comparative study of 2-year outcomes for Hydrus or iStent inject microinvasive glaucoma surgery implants with cataract surgery.

To compare real-world 24-month outcomes of phacoemulsification combined with either iStent inject or Hydrus Microstent. Analysis of data from the Fight Glaucoma Blindness (FGB) international registry. Anonymized data from 344 eyes with mild-to-moderate open-angle glaucoma, normal-tension glaucoma or ocular hypertension that underwent phacoemulsification combined with either iStent inject (224) or Hydrus Microstent (120) were included. Data were adjusted for baseline characteristics using linear regression and propensity score matching. The primary endpoint was a comparison of mean intraocular pressure (IOP) at 24 months. At 24 months, there was no significant difference in IOP reduction between the two groups, consistent across all analyses. The matched cohort showed iStent inject achieved 3.1 mmHg reduction and Hydrus a 2.3 mmHg reduction (p=0.530) and a mean medication reduction of 1.0 for iStent inject versus 0.5 for Hydrus (p=0.081). 5.4% of eyes in the iStent inject group and 7.5% of eyes in the Hydrus group required subsequent procedures to improve IOP control within 24 months. Complications were rare with no significant differences between the groups. Twenty-four-month outcomes showed sustained IOP reduction with a good safety profile for both groups. There was no significant difference in IOP outcomes between the groups. There may be a small additional reduction in glaucoma medication usage following cataract surgery with iStent inject compared to Hydrus.

Adjunctive local treatments for patients with residual pockets during supportive periodontal care: A systematic review and network meta-analysis.

This systematic review and network meta-analysis aimed to evaluate the efficacy of adjunctive locally delivered antimicrobials, compared to subgingival instrumentation alone or plus a placebo, on changes in probing pocket depth (PPD) and clinical attachment level (CAL), in patients with residual pockets during supportive periodontal care. Literature search was performed with electronic databases and by hand until 31 May 2020. Primary outcome was the changes in PPD. The treatment effects between groups were estimated with weighted mean differences (WMD) with 95% confidence intervals (CI) and prediction intervals (PI) by using random-effects network meta-analysis. Twenty-two studies were included. Significantly greater PPD reduction was achieved in chlorhexidine chip group (WMD: 0.65mm, 95% CI: 0.21-1.10) and tetracycline fibre group (WMD: 0.64mm, 95% CI: 0.20-1.08) over 6-month follow-up. Other adjunctive antimicrobial agents achieved non-significant improvements compared to scaling and root planing alone. All differences between adjunctive therapies were statistically non-significant. Similar findings were observed for CAL gain. Adjunctive local antimicrobial agents achieved small additional PPD reduction and CAL gain in residual pockets for a follow-up of up to 6months. Tetracycline fibre and chlorhexidine chip achieved better results than other antimicrobials.

Limiting Bias from Test-Control Interference in Online Marketplace Experiments

Many internet firms use A/B tests to make product decisions. In an A/B test, the typical objective is to measure the total average effect (TATE), which measures the difference between the average outcome if all users were treated and the average outcome if all users were untreated. However, a simple difference-in-means estimator will give a biased estimate of the TATE when outcomes of control units depend on the outcomes of units, an issue we refer to as test-control interference. Practically speaking, this type of interference is quite common in online marketplaces and failure to account for it can lead to estimates that are inflated by a factor of 100\%. Using a simulation built on top of data from Airbnb, this paper considers the use of methods from the network interference literature for online marketplace experimentation. We model the marketplace as a network in which an edge exists between two sellers if their goods substitute for one another. We then simulate seller outcomes, specifically considering a status quo context and treatment context that forces all sellers to lower their prices. We use the same simulation framework to approximate TATE distributions produced by using blocked graph cluster randomization, exposure modeling, and the Hajek estimator for the difference in means. We find that while blocked graph cluster randomization reduces the bias of the naive difference-in-means estimator by as much as 62%, it also significantly increases the variance of the estimator. On the other hand, the use of more sophisticated estimators produces mixed results. While some provide (small) additional reductions in bias and small reductions in variance, others lead to increased bias and variance. Overall, our results suggest that experiment design and analysis techniques from the network experimentation literature are promising tools for reducing bias due to test-control interference in marketplace experiments.

Postoperative epidural analgesia versus systemic analgesia for thoraco-lumbar spine surgery in children.

Postoperative epidural analgesia versus systemic analgesia for thoraco-lumbar spine surgery in children.

Benzalkonium Chloride Provides Remarkable Stability to Liquid Protein Lures for Trapping Anastrepha obliqua (Diptera: Tephritidae).

Hydrolyzed protein lures are widely used to monitor fruit fly pests but are rapidly degraded by microbial activity and must be replaced frequently. To improve the stability of lures, the quaternary ammonium biocide, benzalkonium chloride (BC), was evaluated in mixtures with two hydrolyzed proteins commonly used to monitor Anastrepha spp. The mean number of Anastrepha obliqua adults captured during six consecutive weeks using Captor + borax with the addition of 240 mg BC/liter, not renewed during the test, was similar to Captor + borax that was replaced at weekly intervals and was more effective than Captor + borax without BC. Numbers of A. obliqua flies captured in 30% CeraTrap diluted in water containing 240 mg BC/liter were similar to those caught in traps baited with Captor + borax or 30% CeraTrap without BC in the first 9 d of evaluation but was significantly more effective than both lures after 56 d. After >2 mo of use, 30% CeraTrap containing 240 mg BC/liter remained as effective as newly prepared 30% CeraTrap. The addition of BC to lures reduced surface tension of liquid lures by ~40-50%. However, when BC was increased to 720 mg BC/liter, only a small additional reduction in surface tension was observed and higher concentrations of BC did not increase capture rates. These findings could contribute to reduced costs for trapping networks and the development of long-lasting formulations of liquid protein lures for bait stations and mass-trapping targeted at major tephritid pests.

Cost-effectiveness analysis of different systolic blood pressure targets for people with a history of stroke or transient ischaemic attack: Economic analysis of the PAST-BP study.

BackgroundThe PAST-BP trial found that using a lower systolic blood pressure target (<130 mmHg or lower versus <140 mmHg) in a primary care population with prevalent cerebrovascular disease was associated with a small additional reduction in blood pressure (2.9 mmHg).ObjectivesTo determine the cost effectiveness of an intensive systolic blood pressure target (<130 mmHg or lower) compared with a standard target (<140 mmHg) in people with a history of stroke or transient ischaemic attack on general practice stroke/transient ischaemic attack registers in England.MethodsA Markov model with a one-year time cycle and a 30-year time horizon was used to estimate the cost per quality-adjusted life year of an intensive target versus a standard target. Individual patient level data were used from the PAST-BP trial with regard to change in blood pressure and numbers of primary care consultations over a 12-month period. Published sources were used to estimate life expectancy and risks of cardiovascular events and their associated costs and utilities.ResultsIn the base-case results, aiming for an intensive blood pressure target was dominant, with the incremental lifetime costs being £169 lower per patient than for the standard blood pressure target with a 0.08 quality-adjusted life year gain. This was robust to sensitivity analyses, unless intensive blood pressure lowering reduced quality of life by 2% or more.ConclusionAiming for a systolic blood pressure target of <130 mmHg or lower is cost effective in people who have had a stroke/transient ischaemic attack in the community, but it is difficult to separate out the impact of the lower target from the impact of more active management of blood pressure.

Glaucoma Surgery Calculator: Limited Additive Effect of Phacoemulsification on Intraocular Pressure in Ab Interno Trabeculectomy.

PurposeTo compare intraocular pressure (IOP) reduction and to develop a predictive surgery calculator based on the results between trabectome-mediated ab interno trabeculectomy in pseudophakic patients versus phacoemulsification combined with trabectome-mediated ab interno trabeculectomy in phakic patients.MethodsThis observational surgical cohort study analyzed pseudophakic patients who received trabectome-mediated ab interno trabeculectomy (AIT) or phacoemulsification combined with AIT (phaco-AIT). Follow up for less than 12 months or neovascular glaucoma led to exclusion. Missing data was imputed by generating 5 similar but non-identical datasets. Groups were matched using Coarsened Exact Matching based on age, gender, type of glaucoma, race, preoperative number of glaucoma medications and baseline intraocular pressure (IOP). Linear regression was used to examine the outcome measures consisting of IOP and medications.ResultsOf 949 cases, 587 were included consisting of 235 AIT and 352 phaco-AIT. Baseline IOP between groups was statistically significant (p≤0.01) in linear regression models and was minimized after Coarsened Exact Matching. An increment of 1 mmHg in baseline IOP was associated with a 0.73±0.03 mmHg IOP reduction. Phaco-AIT had an IOP reduction that was only 0.73±0.32 mmHg greater than that of AIT. The resulting calculator to determine IOP reduction consisted of the formula -13.54+0.73 × (phacoemulsification yes:1, no:0) + 0.73 × (baseline IOP) + 0.59 × (secondary open angle glaucoma yes:1, no:0) + 0.03 × (age) + 0.09 × (medications).ConclusionsThis predictive calculator for minimally invasive glaucoma surgery can assist clinical decision making. Only a small additional IOP reduction was observed when phacoemulsification was added to AIT. Patients with a higher baseline IOP had a greater IOP reduction.

Different systolic blood pressure targets for people with history of stroke or transient ischaemic attack: PAST-BP (Prevention After Stroke—Blood Pressure) randomised controlled trial

Objective To assess whether using intensive blood pressure targets leads to lower blood pressure in a community population of people with prevalent cerebrovascular disease.Design Open label randomised controlled trial.Setting 99...

Thresholds of species loss in Amazonian deforestation frontier landscapes.

In the Brazilian Amazon, private land accounts for the majority of remaining native vegetation. Understanding how land-use change affects the composition and distribution of biodiversity in farmlands is critical for improving conservation strategies in the face of rapid agricultural expansion. Working across an area exceeding 3 million ha in the southwestern state of Rondônia, we assessed how the extent and configuration of remnant forest in replicate 10,000-ha landscapes has affected the occurrence of a suite of Amazonian mammals and birds. In each of 31 landscapes, we used field sampling and semistructured interviews with landowners to determine the presence of 28 large and medium sized mammals and birds, as well as a further 7 understory birds. We then combined results of field surveys and interviews with a probabilistic model of deforestation. We found strong evidence for a threshold response of sampled biodiversity to landscape level forest cover; landscapes with <30-40% forest cover hosted markedly fewer species. Results from field surveys and interviews yielded similar thresholds. These results imply that in partially deforested landscapes many species are susceptible to extirpation following relatively small additional reductions in forest area. In the model of deforestation by 2030 the number of 10,000-ha landscapes under a conservative threshold of 43% forest cover almost doubled, such that only 22% of landscapes would likely to be able to sustain at least 75% of the 35 focal species we sampled. Brazilian law requires rural property owners in the Amazon to retain 80% forest cover, although this is rarely achieved. Prioritizing efforts to ensure that entire landscapes, rather than individual farms, retain at least 50% forest cover may help safeguard native biodiversity in private forest reserves in the Amazon.

Hybrid Wing Body Aircraft System Noise Assessment with Propulsion Airframe Aeroacoustic Experiments

A system noise assessment of a hybrid wing body configuration was performed using NASA's best available aircraft models, engine model, and system noise assessment method. A propulsion airframe aeroacoustic effects experimental database for key noise sources and interaction effects was used to provide data directly in the noise assessment where prediction methods are inadequate. NASA engine and aircraft system models were created to define the hybrid wing body aircraft concept as a twin engine aircraft with a 7500 nautical mile mission. The engines were modeled as existing technology, in production, bypass ratio seven turbofans. The baseline hybrid wing body aircraft was assessed at 26.4 dB cumulative below the FAA Stage 4 certification level. To determine the potential for noise reduction with relatively near term technologies, seven other configurations were assessed beginning with moving the engines two fan nozzle diameters upstream of the trailing edge and then adding technologies for reduction of the highest noise sources. Aft radiated noise was expected to be the most challenging to reduce and, therefore, the experimental database focused on jet nozzle and pylon configurations that could reduce jet noise through a combination of source reduction and shielding effectiveness. The best configuration for reduction of jet noise used state-of-the-art technology chevrons with a pylon above the engine in the crown position. This configuration resulted in jet source noise reduction, favorable azimuthal directivity, and noise source relocation upstream where it is more effectively shielded by the limited airframe surface, and additional fan noise attenuation from acoustic liner on the crown pylon internal surfaces. Vertical and elevon surfaces were also assessed to add shielding effectiveness. The elevon deflection above the trailing edge showed some small additional noise reduction whereas vertical surfaces resulted in a slight noise increase. With the effects of the configurations from the database included, the best available noise reduction was 41.5 dB cumulative. Projected effects from additional technologies were assessed for an advanced noise reduction configuration including landing gear fairings and advanced pylon and chevron nozzles. Incorporating the three additional technology improvements, an aircraft noise is projected of 42.9 dB cumulative below the Stage 4 level.

Deficiency of N-glycolylneuraminic acid and Galα1-3Galβ1-4GlcNAc epitopes in xenogeneic cells attenuates cytotoxicity of human natural antibodies

A number of carbohydrate structures apart from Galα1-3Galβ1-4GlcNAc (Gal) have been implicated as potential xenoantigens. Epitopes of another carbohydrate structure, namely N-glycolylneuraminic acid (NeuGc), are widely expressed on the surfaces of endothelial cells of all mammals, except humans, and are likely targets of anti-non-Gal antibodies (Abs). The purpose of this study is to assess whether deficiency of NeuGc and Gal epitopes in xenogeneic cells attenuates the cytotoxicity of naturally occurring antibodies in human sera. We generated mice deficient in both α1,3-galactosyltransferase (GalT) and cytidine monophospho-N-acetylneuraminic acid hydroxylase (CMAH). Flow cytometric and immunohistochemical studies confirmed the complete absence of Gal and NeuGc expression in hematopoietic cells and tissue sections of the heart, lungs, liver, kidney, and pancreas in GalT(-/-) CMAH(-/-) double knockout (DKO) mice. The thymocytes obtained from wild-type (WT), GalT(-/-), CMAH(-/), and DKO mice were used to capture xenoreactive Abs present in human sera from healthy volunteers of each blood group. The titers and complement-dependent cytotoxicity (CDC) of these Abs were determined by flow cytometry and the (51) Cr release assay, respectively. In all sera, IgM and IgG Abs bound to the thymocytes of WT, GalT(-/-), CMAH(-/-), and DKO mice. The average values of IgM Abs against thymocytes of WT and CMAH(-/-) mice were similar, but were statistically higher than those against thymocytes of GalT(-/-) and DKO mice. The average value of IgG Abs against WT mouse thymocytes was similar to that against GalT(-/-) mouse thymocytes, but was significantly higher than that against thymocytes of CMAH(-/-) and DKO mice. Remarkable CDC of human sera was observed against the thymocytes of WT and CMAH(-/-) mice, whereas thymocytes of GalT(-/-) and DKO mice were more resistant to lysis. CDC of human sera against CMAH(-/-) mouse thymocytes was significantly lower than that against WT mouse thymocytes. In addition, CDC against DKO mouse thymocytes, which appeared undetectable even at lesser serum dilutions, was significantly lower than that against GalT(-/-) mouse thymocytes. A DKO mice strain lacking both Gal and NeuGc antigens in several tissues has been generated. Comparing CDC of human sera against mouse thymocytes, the DKO strain shows a statistically significant but a small additional reduction in CDC compared to that already achieved in GalT(-/-) mice.

Effects of UV/H 2O 2 advanced oxidation on chemical characteristics and chlorine reactivity of surface water natural organic matter

The advanced oxidation process utilizing ultraviolet and hydrogen peroxide (UV/H 2O 2) is currently applied in commercial drinking water applications for the removal of various organic pollutants. Natural organic matter (NOM) present in the source water can also be oxidized and undergo changes at the fluence and H 2O 2 concentrations applied in commercial drinking water UV/H 2O 2 applications (fluences less than 2000 mJ cm −2, initial H 2O 2 concentrations less than 15 mg L −1). In this study, the impact of UV/H 2O 2 on NOM’s aromaticity, hydrophobicity, and potential to form trihalomethanes (THMs) and haloacetic acids (HAAs) was investigated for raw surface water and the same water with the very hydrophobic acid (VHA) fraction of NOM removed. During UV/H 2O 2 treatments, NOM in the raw surface water was partially oxidized to less aromatic and hydrophobic characteristics, but was not mineralized, confirming findings from past research. Below fluences of 1500 mJ cm −2 UV/H 2O 2 treatment of the raw water did not lead to reduction in the formation potential of THMs. The formation potential of HAAs was reduced at a fluence of 500 mJ cm −2 with only small additional reductions as fluence further increased. For the water from which the VHA fraction was removed, UV/H 2O 2 treatment led to mineralization of NOM suggesting that, when coupled with a pre-treatment capable of removing the VHA fraction, UV/H 2O 2 could achieve further reductions in NOM. These subsequent reductions in NOM led to continuous reductions in the formation potentials of THMs and HAAs as fluence increased.

Educational inequalities in self-rated health within the Arab minority in Israel: explanatory factors

Studies on factors explaining the socioeconomic inequalities in health within ethnic minorities are scarce. This study examines the contribution of material conditions, and psychosocial, community, cultural and behavioural factors to explaining educational disparities in self-rated health (SRH) within the Arab minority in Israel. In 2005, a national random sample of 902 persons aged 30-70 was selected in a multistage sampling procedure for interviewing. We used multistage logistic regression modelling to examine the percent of attenuations in odds ratios (OR) of extreme categories for education (low vs. high) in the associations with SRH after inclusion of explanatory variables. Education was significantly associated with SRH [odds ratio (OR) = 3.86, 95% confidence interval (CI) = 2.30-6.47]. The separate inclusion of material conditions reduced the OR of poor SRH by 43%. Psychosocial, community or behavioural variables reduced it by 17%, 26% and 11%, respectively. Combining each group of factors with material conditions led to small additional reductions in OR. Integrating all explanatory variables reduced OR by 54%, with the association becoming non-significant. Cultural variables were not associated with SRH and were therefore not included in the multivariate analysis. Material conditions are a major factor in explaining the educational disparities in SRH among Arabs in Israel. Most of the impact of psychosocial and health behaviours, together with part of the community effects, operated through material conditions. Reduction of educational inequalities in SRH requires provision of educational attainment opportunities accompanied by employment opportunities assuring equivalent material gains. Further examination of factors explaining health inequalities among other minorities is warranted.

Function of Neuromuscular Synapses in the Zebrafish Choline-Acetyltransferase Mutantbajan

We have identified a zebrafish mutant line, bajan, in which compromised motility and fatigue result from a point mutation in the gene coding choline acetyltransferase (ChAT), the enzyme responsible for acetylcholine (ACh) synthesis. Although the mutation predicts loss of ChAT function, bajan inexplicably retains low levels of neuromuscular transmission. We exploited this residual activity and determined the consequences for synaptic function. The attenuated synaptic responses were a direct consequence of a decrease in both resting mean quantal size and quantal content. To replicate behavioral fatigue in swimming, motorneurons were stimulated at high frequencies. A prominent reduction in quantal content, reflecting vesicle depletion, was coincident with a small additional reduction in quantal size. In humans, defective ChAT leads to episodic apnea, a form of congenital myasthenic syndrome characterized by use-dependent fatigue. In contrast to bajan, however, afflicted individuals exhibit a normal resting quantal size and quantal content. The fatigue in humans results from a pronounced long-lasting drop in quantal size with little or no change in quantal content. These differences have important implications for interpreting fatigue as well as on understanding the impact of ACh availability on vesicle filling and recycling.

Characteristics of cabin air quality in school buses in Central Texas

This study assessed in-cabin concentrations of diesel-associated air pollutants in six school buses with diesel engines during a typical route in suburban Austin, Texas. Air exchange rates measured by SF 6 decay were 2.60–4.55 h −1. In-cabin concentrations of all pollutants measured exhibited substantial variability across the range of tests even between buses of similar age, mileage, and engine type. In-cabin NO x concentrations ranged from 44.7 to 148 ppb and were 1.3–10 times higher than roadway NO x concentrations. Mean in-cabin PM 2.5 concentrations were 7–20 μg m −3 and were generally lower than roadway levels. In-cabin concentrations exhibited higher variability during cruising mode than frequent stops. Mean in-cabin ultrafine PM number concentrations were 6100–32,000 particles cm −3 and were generally lower than roadway levels. Comparison of median concentrations indicated that in-cabin ultrafine PM number concentrations were higher than or approximately the same as the roadway concentrations, which implied that, by excluding the bias caused by local traffic, ultrafine PM levels were higher in the bus cabin than outside of the bus. Cabin pollutant concentrations on three buses were measured prior to and following the phased installation of a Donaldson Spiracle Crankcase Filtration System and a Diesel Oxidation Catalyst. Following installation of the Spiracle, the Diesel Oxidation Catalyst provided negligible or small additional reductions of in-cabin pollutant levels. In-cabin concentration decreases with the Spiracle alone ranged from 24 to 37% for NO x and 26 to 62% and 6.6 to 43% for PM 2.5 and ultrafine PM, respectively. Comparison of the ranges of PM 2.5 and ultrafine PM variations between repetitive tests suggested that retrofit installation could not always be conclusively linked to the decrease of pollutant levels in the bus cabin.

Distinct Short-Term and Long-Term Adaptation to Reduce Saccade Size in Monkey

In monkeys, saccades that repeatedly overshoot their targets adapt to become smaller by the time the monkey has made 1,000-2,000 saccades. In life, adaptation must keep movements accurate for long periods of time. Previous work describes only saccade adaptation that occurs within a few hours. Here we describe long-term saccade adaptation elicited in three monkeys by 19 days of training. Each day a monkey made saccades to track 16 degrees leftward and rightward target movements. During saccades, the target stepped back toward its starting position 6.4 degrees (40%) in two monkeys or 8 degrees (50%) in the third. After each day's adaptation, we blindfolded the monkey with goggles and returned it to its cage overnight. We found that adapting saccades for 19 days elicited significantly larger, long-lasting reduction in saccade size than did adapting for only 1 day. Further, after 19 days of adaptation we could elicit additional, apparently normal, short-term reduction in saccade size by increasing the size of the intra-saccade target movement. In contrast, we could elicit only small additional size reduction after only 1 day of adaptation. A simple model using separate short- and long-term adaptation mechanisms can reproduce many of the features of saccade gain exhibited by monkeys during a 19-day adaptation. We conclude that there is a long-term saccade-adaptation mechanism that is distinct from the well-characterized short-term system and that this newly recognized system is responsible for long-term maintenance of saccade accuracy.

Identifying and targeting predictors of drop-out from group cognitive behaviour therapy

The predictors of drop-out from a group cognitive behaviour therapy (CBT) program were examined. In Study 1, 6 years of archival data of Perth Clinic's group CBT program were examined to determine the predictors of treatment drop-out. The predictors identified were low self-esteem at admission and a poor relationship status. These predictors were used to generate an algorithm for use by clinicians in identifying patients who may be likely to drop out. In Study 2, a controlled trial was conducted to determine if a brief self-esteem module delivered prior to a group CBT program might enhance outcomes and reduce drop-out rates. Day-patients who received the self-esteem module reported small additional reductions in depression scores but there were no noticeable effects upon drop-out rates. Suggestions are made for other ways to reduce drop-outs in CBT programs.